Spray dispensing containers such as plastic bottles having removable "trigger" or "pump" type sprayer mechanisms have to date been increasingly adopted as a packaging solution for various liquid products. Such spray dispensing containers are both refillable and reusable, and have accordingly found success in terms of their market acceptance by retailers, consumers and other end users.
Typically, a sprayer mechanism for the spray dispensing container will be mounted to a cap for threaded or similarly secured engagement of the sprayer with the liquid container. The cap is often threadedly affixed to the corresponding exterior surface of a neck on the container which defines the container opening or mouth. Unfortunately, such containers, once filled with liquid and assembled with a sprayer mechanism, are at times prone to leakage at the threaded engagement between the sprayer cap and the container neck. This results in product loss and in soiling of labels. In the case of toxic or corrosive liquids, a potential risk to packagers, handlers, shippers, consumers and the environment may also ensue. Regardless of how securely or tightly the threaded engagement is made between the sprayer cap and exterior surface of the container neck, vibration of the container during transport of filled and assembled spray dispensing containers often results in "backing-off", namely in negative rotation or loosening of the threaded cap of the sprayer mechanism with respect to the container neck to which it is affixed. This phenomenon, where sufficiently pronounced, will cause the contained liquid to leak.
The response of the packaging industry to the leakage problem described above has produced a number of solutions, many of which are unsatisfactory. For instance, an adhesive or sealing compound may be applied to fix the threaded engagement between the dispenser mechanism cap and container. However, this solution typically renders the container non-refillable. As well, some manufacturers choose to transport or market filled liquid containers with a separately packaged spray dispenser, such that the consumer or end user is required to assemble the container and dispenser after purchase by removal of a foil or other seal from the opening on the container neck. Such a solution, while effective in preventing leakage, has proven unpopular with consumers due to the required post-sale assembly and poses packaging problems for the manufacturer or shipper who must bundle two separate items together. Yet another solution to the leakage problem is that of wrapping a filled container and spray dispenser assembly with a leak-proof covering, such as shrink-wrapped plastic film. While this solution may prevent leakage of the contained liquid into the surroundings during transport, it may not entirely prevent leakage from the container to within the wrapping itself.
It has also been known in the prior art to provide for sealing mechanisms for spray dispensing liquid containers. For instance, U.S. Pat. No. 3,587,940, issued on Jun. 28, 1971 in the name of Ellis, teaches a conversion kit adapter for liquid dispensers. The kit is said to permit the use of various ejector pumps on cans or receptacles having different kinds of mouths, and is said to provide an airtight seal. The sealing mechanism of the kit is comprised of a multi-part assembly. One of the parts consists of a resilient split ring washer disposed within a threaded cap of the sprayer mechanism. The split ring washer is said to provide sealing engagement with the upper surface of a laterally projecting flange provided around a collar portion of the spray mechanism. The lower surface of the said flange is described as sealingly engaging with another part of the sealing mechanism, namely a resilient retainer ring also disposed within the cap. The retainer ring provides a conical depending guide for the dip tube or pipette of the spray mechanism.
There are a number of problems or shortcomings associated with the sealing mechanism as taught by the Ellis patent referred to above. First, the sealing mechanism is adapted for sprayer mechanisms having a collar portion with a laterally projecting circumferential flange, and does not appear to be suitable for other collar geometries which do not provide such a flange. Second, the teachings of Ellis do not address the leakage problem caused by "backing-off" of the threaded sprayer cap from the container neck to which it is engaged. This is due to the fact that sealing engagement according to the Ellis teachings is achieved when the various parts of the sealing mechanism, namely the split ring washer and resilient retainer ring, are pressed together against the collar portion of the sprayer mechanism as the cap in which they are disposed is screwed onto the neck of the receptacle. Thus, any backing-off of the sprayer cap and container neck engagement would be expected to compromise the effectiveness of the multi-part sealing mechanism as taught by Ellis.
Accordingly, it is an object of the safety seal according to the present invention to address the problem of post-production leakage from spray dispensing containers.